Apparatus for casehardening small objects



G. A. H. MEKER APPARATUS FOR CASE ammsnme SMALL osascws' Filed Feb. 17, 1925 March 9 1926. 1,575,635

rigia 5 E 4 1 1 /AWW A HEP. c 1- Afro/m7 Patented Mar. 9, 1926.

UNITED STATES GEORGES ANTONY HENRI MEKER, or oouRBEvom, FRANCE.

APPARATUS FOR CASEHARDENING SMALL OBJECTS.

Application filed February To all whom it may concern Be it known that I, GEORGESANTONY HENRI MEKER, a citizen of the Republic of France, residing at Courbevoie, Seine, France, have invented certain new and useful Improvements in Apparatus for Casehardening Small Objects, of which the following is a specification.

The object of my invention is to provide a cementation furnace so designed as to enable an absolutely uniform case-hardening of small objects'to be obtained.

Cement-ation in fixed boxes does not permit the uniform carbureting of small objects to be effected because those nearest the walls of the box become heated to cementation temperature before those in the center. The only certain remedy consists in imparting a continuous motion to the objects and to the carbureting agent during the operation.

My present invention does, however, ensure the result sought for by providing a furnace of the rota.ry.type where the objects are put into a specially shaped basket or box which is inserted ina tube and rotated therewith, while permitting the temperature prevailing in the center of the box to be measured.

In order to make my invention more clearly understood I have illustrated an embodiment thereof in and by drawings appended hereto and wherein:

Figure 1 is a vertical longitudinal section of the furnace.

Figure 2 is a detail sectional view of the cementation box with its operating handle.

Figure 3 is an end View of the same.

Figure 4 is a section on line l4: of Figure 2.

Figure 5 is a section of theouter tube taken on line 55 of Figure 1.

In all the figures the same reference letters denote the same parts.

Referring to the drawings A is the metal tube driven by a wheel B actuated in its turn by a worm G. But the means by which the metal tube is rotated may be any. Tube A rests on two sets of two rollers d and cl. The central part of the tube is disposed within and heated by a refractory furnace E, comprising a burner F if the furnace. is a gas one, or any other source of heat. The tube has a partition Gr cast in one piece with it and is filled between this partition and 17, 1925. Serial No. 9,857.

the driving wheel B with refractory heatinsulating material.

The cementation basket or box H is shown in detail in Figure 2. It is protected against exterior radiation by a removable plug H made of some refractory substance: asbestos or such like. Box His, for instance, in the shape of a cylinder, the inner end of which carries a handle 72.

Box H is cut away at its upper part to for1n an'opening 2' (Figure 4), in order to permit the loadlng and unloading of material. Duct h bored through handle it of the box affords a passage for a pyrometer. In order to rigidly connect the box with tube A during rotation thereof, the'said box is provided at diametrically-opposite points with two longitudinal ribs or beads I, while tube A has hollow grooves J registering therewith.

As will be apparent this device, once set and kept in position by a suitable stop, constitutes a rotary closed box.

I have only to stop the tube in a predetermined position in order to withdraw the box, thereby withdrawing at the same time all the objects treated therein. I can-then tilt them at once into the tempering tank,

reload the box while hot and put it back into the furnace again.

Under such conditions I obtain a uniform case-hardening of all the objects contained in the box for, contrary to what is the case with all hitherto known devices, all the objects are equally exposed to heat action and can immediately after cementation bepitched at one throw into the tempering tank.

Having now particularly ascertained and described the nature of my said invention as well as the manner in which the same'is to be performed, I declare that what I claim 1. Apparatus for case-hardening small obj ects, comprising a furnace having a heating chamber; a metal tube extending axially through said chamber and having its central portion disposed within the same, said tube being open at one end and constituting, with the furnace, a pair of companion elements, one of which is adapted to be positively rotated; mechanism for driving said rotatable element; a removable cementation basket for containing the objects to be treated adapted to be inserted into and withdrawn from the tube through the open end thereof; and

means for positioning said basket in the said centralportion of the tube. v

2, Apparatus for case-hardening small ob-v jects, comprising a furnace having an internal heating chamber; a metal tube extending through and beyond said chamber and provlded with an nternal stop which is 10-.

cated within the confines of the portion of the tube dispose-d the chamber, said tube being open at the end remote from said partition and constitutingmith the furnace,

a pair of companion elements, one of Whichis adapted to be positively rotated; mechav nisn for driving said rotatable element; and

a removable cementation basket for containing the ob ects to be treated, adapted to be i/ inserted throughlthe open end of the tube intoengagement with said stop to position U nal heating chamber; a, n'1etal,tube extending.through and beyond said chamber and.

provided ,with an internal stop which is lo-,, cated within the confines of the portion of the tubedispose-d in the chamber, said tube. .being open at the end remote from said partition and constituting, with the furnace,

nismfor, driving said rotatable element; a

-. the objects to. betreated adapted to be insorted through the open end of. the tube into ,engagement with said. stop toposition it it within the aforesaid portion of the tube disposed within the chamber.

3. Apparatus for case-hardening small ob-,

jects, comprising a furnace having an intera pair of companion elements, one of which is, adapted to be positively rotated; mecharemovable oementation basket for containing ,within the aforesaid portion of the tube dis- 3 posed withinsaid chamber; and a removable .plugfitted in the open end of thetube.

4. Apparatus for case-hardening. .small objects, comprising a.-furnace having a heat- .ing chamber;.a rotatable metal tube extendc ;ing...aX1ally. through said chamber and hav- .'ing its central. portion. disposed within the ,,.samesa1d tube having an open end; mech- .anlsm. forv rotating said. tube relatively to thehfurnace and its. chamber; a remov- .abl etcementation basket for containing the .Hobjectsto be treated adapted to be inserted chamber extendmg axially therethrough and having an open end; a cementation basket into and withdrawn from the tube through the open end thereof; means for positioning the basket within the. said central por internal stop situated ithinthe central portion of the tube and against which the inner end of the basket abuts.

7, Apparatus forcase hardening small obje cts, comprising a furnace having a heating chamber; a rotatable-metal tube extending axially through said chamber and having its central portion disposedwithin the same; mechanismfor rotating said tube relat vely to the furnace and its chamber, a

cementation. basket for containing the objects to. be treated adapted to be inserted into and withdrawn from the central portion ofthe tube through one; end thereof; means for connecting the basket to the tube to rotate therewitllyan-d heat-insulating material fitting in the tube at oppositesides of the basket, thematerial-at one .side constituting a plug which is removable from the tube to enable the insertion and withdrawal of the basket.

8. Apparatus.forcase hardening small objects, comprising a furnace having a heating a tubular supporting element for containing the objects to be treated adapted to be inserted into andwithdrawn from said element through 1tsopen end; means for eifectlnga relative rotary movement betweenthe furnace and the basket; and an elongated handle on saidbasket extending outward.therefrom through .said

open end and having anaigial ,bore which opens into thebasket to ireceive a pyrometer. In testimony whereof L aflix my signature.

GEQRGES ANTONY HENRIQMEKER. 

